The present invention relates to methods of measuring coupling ratios. Moreover, the invention also concerns systems and apparatus operable to employ the methods for measuring such coupling ratios. Such coupling ratios concern, for example, marine vessels regarding power coupling from their engines or motors via associated transmissions to corresponding one or more propellers.
The present invention relates to methods of measuring coupling ratios. Moreover, the method is especially suitable for measuring coupling ratios in marine vessels. Referring to FIG. 1, a contemporary known marine vessel is indicated generally by 10. The marine vessel 10, for example a private boat, comprises a hull 20 complemented with an upper deck 30 above which is included a control cabin 40. The control cabin 40 includes various user-operable controls such as a steering wheel 50 for steering a direction of travel of the vessel 10 in operation, and a speed controller 60 having a control lever 70 which is user-adjustable for controlling in operation speed of travel of the vessel 10 in forward and reverse directions as will be elucidated in more detail later; a user 80 is thereby able to steer and control movement of the vessel 10 in forward or reverse directions by manipulating the steering wheel 50 and the control lever 70. Within the hull 20, the vessel 10 comprises an engine or motor 100 having an output shaft 110 which is driven in operation by the engine or motor 100 in a uni-directional rotation manner as denoted by an arrow 120. The shaft 110 is coupled to a rotary input of a transmission 130, also known as a “coupling”; the transmission 130 can optionally include one or more of a clutch and a gear. The transmission 130 includes a toothed output drive wheel with a given number of teeth and optionally a rotation sensor operable to provide a signal indicative of a rotation rate of the toothed drive wheel for the purposes of the present invention as will be elucidated later, the number of teeth of the output drive does not need to be known. An output shaft 140 of the transmission 130 coupled to the aforementioned output drive wheel is operable to be driven bi-directionally in both clockwise and anti-clockwise directions as denoted by an arrow 150 in response to user-adjustment of the control lever 70. The output shaft 140 is further coupled at its remote end to one or more propellers 160 which are also susceptible to being driven bi-directionally as denoted by an arrow 170 is response to user-adjustment of the lever control 70. The aforementioned control lever 70 is coupled, optionally via a data processor in the speed controller 60, to the transmission 130 so that adjustment of the control lever 70 is operable to control a degree of coupling of rotary power from the engine or motor 100 through the transmission 130 to the one or more propellers 160. Moreover, the vessel 10 is designed to float on water 200 with its one or more propellers 160 immersed in the water 200 as illustrated.
The control lever 70 and its associated speed controller 60 are illustrated in more detail in plan view in FIG. 2. The control lever 70 is pivotally movable within a slot 250 having a central neutral position denoted by a transverse axis 300. Moreover, the speed controller 60 includes a graduated scale 310 having a central marking 440 corresponding to the aforesaid neutral position of the control lever 70. In a forward control position denoted by a symbol “F”, the graduated scale 310 has a first series of markings 41Of, 42Of, 43Of, 44Of as illustrated corresponding to progressively increasing forward speed, namely corresponding to progressively less slippage occurring between coupling plates of the transmission 130 when propelling the vessel 10 in a forward direction. In a similar manner, the graduated scale 310 has a second series of markings 41Or, 42Or, 43Or, 44Or as illustrated corresponding to progressively less slippage occurring between the coupling plates of the transmission 130 when propelling the vessel 10 in a reverse direction. The aforesaid neutral position 440 for the control lever 70 corresponds, effectively, to complete slippage between the coupling plates of the transmission 130, namely a state of non-coupling of mechanical power through the transmission 130.
A problem encountered in practice is that the vessel 10 is often customized or is unique in its configuration of motor or engine 100, its transmission 130, and its one or more propellers 160 and also speed controller 60. It is thus desirable that the vessel 10 should be easily configurable so that a position of the control lever 70 relative to the scale 310 is representative, namely visually indicative, of a manner in which the vessel 10 is susceptible to operating in coupling power from the engine or motor 100 to the one or more propellers 160. In other words, it is desirable that the control lever 70 positioned at the neutral position 440 should correspond to substantially negligible rotary power being transmitted through to the one or more propellers 160; in contradistinction, it is also desirable that the control lever 70 adjusted by the user to align to the markings 440f, 44Or should correspond to full coupling of rotary power from the engine or motor 100 to the one or more propellers 160 so that substantially negligible slippage occurs in the transmission 130. Moreover, it is also desirable that intermediate markings, for example the markings 42Of, 42Or should correspond to substantially half coupling of rotary power from the motor or engine 100 to the one or more propellers 160 in forward and reverse directions respectively.
When the vessel 10 has initially been constructed, or has been subject to modifications or alterations, the control lever 70 will often be non-representative of characteristics of rotary power transmission occurring within the vessel 10. A conventional approach contemporarily adopted for the vessel 10 is to input various parameters into the speed controller 60, for example into an electronic data processor thereof (not shown in FIG. 1), so as to result in the position of the control lever 70 relative to the scale 310 being representative of rotary power transmission occurring within the vessel 10. Such data entry is not only cumbersome and time consuming, but also requires knowledge of specific characteristics of the motor or engine 100, the transmission 130 and also the one or more propellers 160.
The present invention therefore seeks to address technical problems encountered with the vessel 10 when implemented in substantially conventional form, by providing a more practical and straightforward method of measuring coupling ratios in a rotary transmission chain in the vessel 10.
Various configurations for the transmission 130 are known in earlier literature, although methods of measuring coupling ratios and providing corresponding calibrations of speed controls is not elucidated in such literature. For example, in a Japanese patent application JP 2003-002296, there is described a hydraulic control mechanism for a marine reduction reversing gear. The hydraulic control mechanism is directed at a technical problem of allowing for changes of two ranges of set values of propeller rotating speed control and slip factor control for a marine reduction reversing gear fixed to a rear part of an engine. The control mechanism is operable to change rotation of a propeller for a ship ahead and astern to change speed. Moreover, the control mechanism is capable of accommodating changes in control by increasing and/or decreasing operating oil pressure applied to the hydraulic clutch.
Moreover, in a Japanese patent application JP 07-196090, there is described a slip quantity adjuster for ship marine gears. The adjuster is operable to address a technical problem of providing a convenient approach to setting a control range of a dial to a full range whilst permitting a user to input a number of revolutions of a screw shaft, for example the screw shaft being coupled to a propeller. Such adjustment is provided via a solenoid valve hydraulically controlling a clutch of a marine gear. Moreover, the adjuster employs an electronic PID control unit in connection with a PWM circuit.
The aforementioned Japanese applications describe approaches to controlling power transmission through clutches of marine engine or motor systems but does not disclose a more convenient approach to measuring coupling ratios within such systems.
It is desirable to provide a more practical and straightforward method of measuring coupling ratios in transmission chains of marine vessels.
According to a first aspect of the invention, there is provided a method of measuring coupling ratios in a marine vessel, said vessel comprising:    (a) a source of mechanical power;    (b) a coupling system operatively coupled via a first input shaft to said source of power and operatively coupled via a second output shaft to one or more propellers of said vessel; and    (c) a controller coupled to a user interface and also to the coupling system such that the user interface is operable via the controller to control a degree of power coupling occurring in operation through the coupling system,    said first and second shafts being provided with first and second rotation rate sensors respectively coupled to said controller for generating first and second rotation rate signals indicative in operation of rotation rates of said first and second shafts respectively, wherein said method includes at least one of steps (d) to (e), such steps including:    (d) adjusting the user interface to invoke substantially full engagement of coupling in the coupling system such that substantially full coupling of the source of power to said one or more propellers occurs corresponding to propelling the vessel at substantially full forward speed, and recording corresponding values of said first and second indicative signals in said controller; and    (e) adjusting the user interface to invoke substantially full engagement of coupling in the coupling system such that full coupling of the source of power to said one or more propellers occurs corresponding to propelling the vessel at substantially full reverse speed, and recording corresponding values of said first and second indicative signals in said controller.
The invention is of advantage in that the values of the first and second indicative signals recorded in the controller are susceptible to being used to calculate an effective measure of a coupling ratio provided in the vessel.
“Full forward speed” corresponds to substantially full coupling employed in the coupling system.
Optionally, the method comprises a further step of:    (f) calibrating said user interface based on measurements in at least one of steps (d) and (e) so that said user interface when calibrated is operable to provide a user-interpretable indication when full power is being coupled through the coupling system such that intermediate indications of the user interface are indicative of progressively changing degrees of couple of power from the first shaft to the second shaft through the coupling system.
Optionally, the method includes further steps of:    (g) adjusting the user interface to invoke full slippage to occur within the coupling system so that mechanical power is substantially not coupled from the first shaft to the second shaft such that said second rate sensor is operable to measure substantially zero rotation rate of the second shaft; and    (h) calibrating said user interface based on measurements in step (g) so that said user interface when calibrated is operable to provide a user-interpretable indication when substantially zero power is being coupled through the coupling system. Steps (g) and (h) are of benefit in that they enable a neutral central position to be determined for the user interface.
Optionally, in the method, the user interface is operable to provide a user indication of an effective coupling ratio provided in the vessel.
Optionally, the method is adapted for implementation when the vessel is either on land or floating on water. The method is of benefit that it can be applied when, for example, the vessel is in dry-dock undergoing upgrades or routine repairs.
Optionally, the method is adapted for implementation to recalibrate the vessel after said vessel has been subject to reconfiguration.
Optionally, in the method, the user interface includes at least one of: a linearly-adjustable control, a rotary-adjustable control, a virtual control presented as a symbol on a display with associated inputs for user-manipulation of said virtual control. Such implementations of the user interface are convenient when the vessel is being used under marine conditions, for example storm conditions or conditions of poor visibility.
Optionally, in the method, the coupling system includes coupling plates operable to couple mechanical power thereacross in response to a control signal generated by said controller, said coupling of power across said coupling plates being responsive to a degree of slippage occurring between said plates.
According to a second aspect of the invention, there is provided a marine vessel comprising:    (a) a source of mechanical power;    (b) a coupling system operatively coupled via a first input shaft to said source of power and operatively coupled via a second output shaft to one or more propellers of said vessel; and    (c) a controller coupled to a user interface also to the coupling system such that the user interface is operable via the controller to control a degree of coupling occurring in operation in the coupling system,    said first and second shafts being provided with first and second shaft rotation rate sensors respectively coupled to said controller for generating first and second rotation rate signals indicative in operation of rotation rates of said first and second shafts respectively,said vessel being operable to be calibrated according to the method according to the first aspect of the invention.
According to a third aspect of the invention, there is provided software recorded on a data carrier, said software being executable on computing hardware for implementing the method according to the first aspect of the invention.
It will be appreciated that features of the invention are susceptible to being combined in any combination without departing from the scope of the invention as defined by the accompanying claims.